Practical relevance of prescribing superimposition for determining a frontal sinus pattern match.

A research that tested the methods suitable for comparing ante- and post-mortem radiographic patterns of frontal sinuses concluded that superimposition should be followed as a stringent method for establishing individual identification. We verified the practical relevance of prescribing superimposition by superimposing ante- and post-mortem frontal sinus patterns recorded in case situations as well as simulated ante- and post-mortem of frontal sinus patterns recorded using archived skulls. For superimposition, the wipe facility available in the vision mixer was employed in addition to the mix mode. Ante- and post-mortem radiographic patterns that were available in two earlier cases were not superimposable. Related simulated ante- and post-mortem radiographic patterns of frontal sinuses are superimposable only when the skull that is initially oriented for recording the ante-mortem radiograph is retained in the same posture for recording the post-mortem radiograph also. Once the skull has been removed from the X-ray table, after recording the simulated ante-mortem radiograph, and repositioned for the simulated post-mortem radiograph, even when the intervening time is 1min, the sinus patterns in these radiographs are not superimposable. Superimposition cannot be used as a conditional requirement for side-by-side comparison of radiographic patterns of frontal sinuses.